1、BRITISH STANDARD BS ISO/IEC 16388:2007 Information technology Automatic identification and data capture techniques Code 39 bar code symbology specification ICS 01.080.50; 35.040 BS ISO/IEC 16388:2007 This British Standard was published under the authority of the Standards Policy and Strategy Committ
2、ee on 31 July 2007 BSI 2007 ISBN 978 0 580 56257 0 National foreword This British Standard was published by BSI. It is the UK implementation of ISO/IEC 16388:2007. It supersedes BS ISO/IEC 16388:1999 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee IST
3、/34, Automatic identification and data capture techniques. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Co
4、mpliance with a British Standard cannot confer immunity from legal obligations. Amendments issued since publication Amd. No. Date Comments Reference number ISO/IEC 16388:2007(E)INTERNATIONAL STANDARD ISO/IEC 16388 Second edition 2007-05-15 Information technology Automatic identification and data cap
5、ture techniques Code 39 bar code symbology specification Technologies de linformation Techniques didentification automatique et de capture des donnes Spcifications des symbologies des codes barres, code 39 BS ISO/IEC 16388:2007ii iii Contents Page Foreword iv Introduction v 1 Scope . 1 2 Normative r
6、eferences . 1 3 Terms and definitions. 1 4 Requirements 1 4.1 Symbology characteristics 1 4.2 Symbol structure 2 4.3 Character encodation. 2 4.4 Dimensions 4 4.5 Reference decode algorithm . 5 4.6 Symbol quality 6 4.7 Application-defined parameters 7 Annex A (informative) Additional features. 9 Anne
7、x B (informative) Guidelines for the use of Code 39 12 Annex C (normative) Symbology identifier . 15 Annex D (informative) Example of application-defined parameters . 16 Bibliography . 18 BS ISO/IEC 16388:2007iv Foreword ISO (the International Organization for Standardization) and IEC (the Internati
8、onal Electrotechnical Commission) form the specialized system for worldwide standardization. National bodies that are members of ISO or IEC participate in the development of International Standards through technical committees established by the respective organization to deal with particular fields
9、 of technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the work. In the field of information technology, ISO and IEC have established a joi
10、nt technical committee, ISO/IEC JTC 1. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of the joint technical committee is to prepare International Standards. Draft International Standards adopted by the joint technical committe
11、e are circulated to national bodies for voting. Publication as an International Standard requires approval by at least 75 % of the national bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO and IEC shall n
12、ot be held responsible for identifying any or all such patent rights. ISO/IEC 16388 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 31, Automatic identification and data capture techniques. This second edition cancels and replaces the first edition (I
13、SO/IEC 16388:1999), which has been technically revised. BS ISO/IEC 16388:2007v Introduction The technology of bar coding is based on the recognition of patterns encoded in bars and spaces of defined dimensions. There are numerous methods of encoding information in bar code form, known as symbologies
14、. Code 39 is one such symbology. The rules defining the translation of characters into bar and space patterns and other essential features are known as the symbology specification. In the past, symbology specifications were developed and published by a number of organizations, resulting in certain i
15、nstances in conflicting requirements for certain symbologies. Manufacturers of bar code equipment and users of bar code technology require publicly available standard symbology specifications to which they can refer when developing equipment and application standards. BS ISO/IEC 16388:2007blank1 Inf
16、ormation technology Automatic identification and data capture techniques Code 39 bar code symbology specification 1 Scope This International Standard specifies the requirements for the bar code symbology known as Code 39; it specifies Code 39 symbology characteristics, data character encodation, dim
17、ensions, tolerances, decoding algorithms and parameters to be defined by applications. It specifies the Symbology Identifier prefix strings for Code 39 symbols. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, onl
18、y the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO/IEC 646, Information technology ISO 7-bit coded character set for information interchange ISO/IEC 15416, Information technology Automatic identification and data
19、 capture techniques Bar code print quality test specification Linear symbols ISO/IEC 15424, Information technology Automatic identification and data capture techniques Data Carrier Identifiers (including Symbology Identifiers) ISO/IEC 19762-1, Information technology Automatic identification and data
20、 capture (AIDC) techniques Harmonized vocabulary Part 1: General terms relating to AIDC ISO/IEC 19762-2, Information technology Automatic identification and data capture (AIDC) techniques Harmonized vocabulary Part 2: Optically readable media (ORM) 3 Terms and definitions For the purposes of this do
21、cument, the terms and definitions given in ISO/IEC 19762-1 and ISO/IEC 19762-2 apply. 4 Requirements 4.1 Symbology characteristics The characteristics of Code 39 are as follows. a) Encodable character set: 1) full alphanumeric A to Z and 0 to 9 (ASCII characters 65 to 90 and 48 to 57 inclusive, in a
22、ccordance with ISO 646). BS ISO/IEC 16388:20072 2) special characters: space $ % + - . / (ASCII characters 32, 36, 37, 43, 45, 46 and 47, respectively, in accordance with ISO 646). 3) start/stop character. b) Code type: discrete. c) Elements per symbol character: 9, of which 3 wide and 6 narrow, com
23、prising 5 bars and 4 spaces. d) Character self-checking: yes. e) Data string length encodable: variable. f) Bidirectionally decodable: yes. g) Symbol check character: one, optional (see Annex A). h) Symbol character density: 13 to 16 modules per symbol character, inclusive of minimum intercharacter
24、gap, depending on wide/narrow ratio. i) Non-data overhead: equivalent to 2 symbol characters. 4.2 Symbol structure As illustrated in Figure 1, Code 39 symbols shall comprise a) leading quiet zone; b) start character; c) one or more symbol characters representing data (including symbol check characte
25、r, if present); d) stop character; e) trailing quiet zone. A space, the intercharacter gap, shall separate characters within the symbol. QUIET ZONE START CHARACTER “1“ “A“ STOP CHARACTER QUIET ZONE 1AFigure 1 Code 39 symbol 4.3 Character encodation 4.3.1 Symbol character structure Each symbol charac
26、ter comprises nine elements (five bars and four spaces) of which six are always narrow (either three narrow bars and three narrow spaces, or five narrow bars and one narrow space) and three are always wide (one wide space and two wide bars when there are three narrow bars, or three wide spaces when
27、there are five narrow bars). This parity feature enables character self-checking to be carried out. BS ISO/IEC 16388:20073 4.3.2 Symbol character assignments Table 1 defines all the Code 39 character assignments. Table 1 Code 39 character assignments Char. Encodation Pattern BSBSBSBS B ASCII value 0
28、 00011010 0 4 8 1 10010000 1 4 9 2 00110000 1 5 0 3 10110000 0 5 1 4 00011000 1 5 2 5 10011000 0 5 3 6 00111000 0 5 4 7 00010010 1 5 5 8 10010010 0 5 6 9 00110010 0 5 7 A 10000100 1 6 5 B 00100100 1 6 6 C 10100100 0 6 7 D 00001100 1 6 8 E 10001100 0 6 9 F 00101100 0 7 0 G 00000110 1 7 1 H 10000110 0
29、 7 2 I 00100110 0 7 3 J 00001110 0 7 4 K 10000001 1 7 5 L 00100001 1 7 6 M 10100001 0 7 7 N 00001001 1 7 8 O 10001001 0 7 9 P 00101001 0 8 0 Q 00000011 1 8 1 R 10000011 0 8 2 S 00100011 0 8 3 BS ISO/IEC 16388:20074 Char. Encodation Pattern BSBSBSBSB ASCII value T 000010110 8 4 U 110000001 8 5 V 0110
30、00001 8 6 W 111000000 8 7 X 010010001 8 8 Y 110010000 8 9 Z 011010000 9 0 hyphen 010000101 4 5 period 110000100 4 6 space 011000100 3 2 $ 010101000 3 6 / 010100010 4 7 + 010001010 4 3 % 000101010 3 7 S/S or * 010010100n o n e NOTE 1 S/S denotes the start and stop character, usually graphically repre
31、sented as * NOTE 2 In the columns headed B and S, 0 represents a narrow element and 1 a wide element. 4.3.3 Start and stop characters The Code 39 start and stop character is usually depicted in human-readable form by a * (asterisk). This character shall not form part of the data encoded elsewhere in
32、 the symbol and shall not be transmitted by the decoder. The start character shall be positioned at the normal left end of the data symbol characters, separated from the first bar of the leading data character by an intercharacter gap. The stop character shall be positioned at the normal right end o
33、f the data symbol characters (including symbol check character if present), separated from the final bar of the trailing data character by an intercharacter gap. 4.3.4 Optional symbol check character Annex A defines the symbol check character position and calculation. 4.4 Dimensions Code 39 symbolog
34、y shall use the following nominal dimensions. a) Width of narrow element (X): the X dimension of Code 39 symbols should be defined by the application specification having due regard to the availability of equipment for the production and reading of symbols and complying with the general requirements
35、 of the application. See 4.7.1. b) Wide/narrow ratio (N): 2,0 : 1 to 3,0 : 1. BS ISO/IEC 16388:20075 c) Width of intercharacter gap (I): 1) minimum: equal to X; 2) maximum: for X 0,287 mm: 5,3X; for X 0,287 mm: 1,52 mm or 3X, whichever is greater. d) Minimum width of quiet zone: 10X. e) Recommended
36、minimum bar code height for manual scanning: 5,0 mm or 15 % of symbol width excluding quiet zones, whichever is greater. NOTE The width, W (in millimetres), of a Code 39 symbol, including quiet zones, can be calculated from the following expression: () () ( ) 23 6 1 2 =+ + + WC NXCIQ where W is the
37、symbol width; C is the number of data characters (including symbol check character if used); N is the wide/narrow ratio; X is the width of a narrow element in millimetres; l is the width of the intercharacter gap in millimetres; Q is the width of the quiet zone in millimetres. 4.5 Reference decode a
38、lgorithm Bar code reading systems are designed to read imperfect symbols to the extent that practical algorithms permit. This section describes the reference decode algorithm used in the computation of the decodability value described in ISO/IEC 15416. a) Confirm presence of a leading quiet zone. b)
39、 For each symbol character (including start and stop characters): 1) Measure the total width of 5 bars and 4 spaces; call this S. 2) Compute a threshold value, T = S / 8. 3) Compare each element width for that character with the value T. If element width is greater than T, assume element is wide; if
40、 not, assume element is narrow. 4) Determine if pattern of wide and narrow elements matches a valid character from the allowable set. c) The first symbol character read must be a start/stop character, from which the scan direction can be deduced. d) Continue character reading until a valid start/sto
41、p character is encountered. e) Confirm presence of a trailing quiet zone. BS ISO/IEC 16388:20076 4.6 Symbol quality 4.6.1 Test specification In order to verify whether a symbol meets the specifications in this International Standard it shall be tested using the test specification defined in ISO/IEC
42、15416, which defines a standardized methodology for measuring and grading bar code symbols, as supplemented in 4.6.2. ISO/IEC 15416 lays down conditions under which measurements should be made; and defines methods of determining an overall quality grade based on the attributes of the bar code symbol
43、. The reference decode algorithm defined in 4.5 shall be used for the assessment of the “decode“ and “decodability“ parameters under ISO/IEC 15416. The overall symbol grade shall be expressed in the form shown in the following example: 1,5 / 10 / 660 where 1,5 is the overall symbol quality grade; 10
44、 is the measuring aperture reference number (in this example 0,25 mm diameter); 660 is the peak response wavelength in nanometres. ISO/IEC 15416 allows for additional pass/fail criteria to be stipulated by a symbology specification. For Code 39, the additional criteria are given in 4.6.2. Any indivi
45、dual scan profile which does not meet these requirements shall receive a grade of 0. 4.6.2 Additional parameters 4.6.2.1 Wide/narrow ratio Symbols shall be produced with a nominal N from 2,0 to 3,0 inclusive. The measured value of N in any scan profile shall be in the range 1,8 to 3,4 inclusive. The
46、 wide/narrow ratio in the scan reflectance profile under ISO/IEC 15416 shall be measured and graded as follows. 1,8 N 3,4: Grade 4. N 3,4: Grade 0. 4.6.2.2 Intercharacter gap For symbols with a measured narrow element width (Z) less than 0,287 mm, the maximum allowed intercharacter gap is 5,3Z. For
47、symbols with Z greater than or equal to 0,287 mm, the maximum intercharacter gap is the greater of 3Z or 1,52 mm. Each intercharacter gap in the scan reflectance profile under ISO/IEC 15416 shall be measured and graded as follows. I G max : Grade 4. I G max : Grade 0. where G max= 5,3Z for Z 0,287 m
48、m or G max= MAX(1,52 mm, 3Z) for Z 0,287 mm BS ISO/IEC 16388:20077 4.6.2.3 Quiet zone The quiet zone at each end of the symbol shall be a minimum of 10Z. Both left and right quiet zones on each scan reflectance profile under ISO/IEC 15416 shall be measured and graded as follows. Quiet Zone 10Z: Grad
49、e 4. Quiet Zone 10Z: Grade 0. NOTE In 4.6.2.1 to 4.6.2.3, the requirements are based on the actual, rather than intended, measurements of the parameter; for this reason the Z dimension is appropriate rather than the X dimension. 4.7 Application-defined parameters 4.7.1 Symbology and dimensional characteristics In
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